Flap folding mechanism for bagmaking machines



Oct. 12, 1954 A. J. EVERS FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES e Shee ts-Sheet 1 Filed June 2, 1952 R mm I m; 1; b 5 am 7 o 000 o o I a 0 R. u an. Tfi u b :Jqih \l 1/ F 1 h v r S Q oooooo: P m 1 QR o o E 5 Q o G o 0 0 o p O w 6 Q LU A. J. EVERS FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES Oct. 12, 1954 6 Sheets-Sheet 2 Filed June 2, 1952 Oct. 12, 1954 A. J. EVERS FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES 6 Sheets-Sheet 3 Filed June 2, 1952 INVEINTOR. 011%? JEver5.

BY v 0397211.

Oct. 12, 1954 A. J. EVERS FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES 6 Sheets-Sheet 4 Filed June 2, 1952 INVENTOR. a'rfiar JEwers.

Oct. 12, 1954 A. J. EVERS FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES 6 Sheets-Sheet 5 Filed June 2, 1952 Oct. 12, 1954 FL EVERS FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES Filed June 2, 1952 6 Sheets-Sheet 6 INVENTOR. G rihar J E(W7S. BY

Patented Oct. 12, 1954 FLAP FOLDING MECHANISM FOR BAGMAKING MACHINES- Arthur J. Evers, Brooklyn, N. Y., assignor to International Paper Company, New York, N. Y., a corporation of New York Application June 2, 1952, Serial No. 291,157

11 Claims.

This invention relates to new and useful improvements in bagmaking machines and particularly seeks to provide novel mechanisms for folding the trailing bottom flaps of automatic or selfopening square paper bags as they are being produced by a machine.

Earlier forms of folders for the bottom flaps of automatic or self-opening square bags have been satisfactory when the machines they are used in conjunction with have been operated at relatively slow speeds. However, high speed operations have resulted in repeated mechanical failures of the earlier forms of flap folders due to the increased vibration and resultant parts wear or to the fact that the earlier forms of flap folders were unable to effect the folding of the trailing bottom flap under conditions of sufficiently precise control.

Flap folding mechanisms constructed in accordance with the present invention are adaptable for use in connection with any type of machine for producing automatic or self-opening square or similar types of bags, but are particularly adaptable for use in connection with such machines when designed for high speed operation.

An object of this invention is to provide a machine for producing automatic or self-opening square bags in which are incorporated novel flap folding mechanisms adapted to successfully fold the trailing flaps of bags being produced thereon when such machines are operated at high speeds.

Another object of this invention is to provide flap-folding mechanisms of the character stated which include a pair of rotors operatively associated with said machine to either side of the bottom-forming cylinder thereof with each rotor being provided with a flap-folding finger adapted to be moved in a compound curvilinear path overlying the surface of the cylinder and moving at a speed of advance greater than the peripheral speed of the associated cylinder.

A further object of this invention is to provide flap-folding devices of the character stated in which the projecting fingers carried by the rotors thereof are maintained in fixed angular position in one plane while being bodily moved through an orbital path and oscillated slightly in a plane normal to that of the general plane of rotation whereby to cause the ends of the fingers to generally conform to the curvature of the surface of the associated cylinder during the time that such finger ends overlie the same.

Another object of this invention is to provide mechanisms of the character stated in which each finger is rotatably carried by one end of its associated rotor and is gear-connected to the rotor mounting means whereby to be maintained in fixed angular position in one plane while being bodily moved through an orbital path.

A further object of this invention is to provide mechanisms of the character stated in which the oscillation of the flap-folding fingers in a plane normal to that of the general plane of rotation is effected through cam and follower connections between the rotor and the finger.

A further object of this invention is to provide mechanisms of the character stated which are simple in design, rugged in construction and economical to manufacture.

With these and other objects in view, the nature of which will be more apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description, and the appended claims.

In the drawings:

Fig. 1 is a side elevation of the bottomer end of an automatic bag machine containing flap-folding mechanisms constructed in accordance with this invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a schematic side elevation showing the gear train driving certain Of the parts of the machine;

Fig. 4 is a top plan view of the gear train shown in Fig. 3;

Fig. 5 is a fragmentary horizontal section taken through the base of the machine and shows the main driving motor, back shaft and transverse shafts for transmitting power to the various operative parts of the machine;

Fig. 6 is an enlarged fragmentary side elevation, partly in section, of the cylinder portion of the bottomer and shows two stations of the cylinder, the one at the upper right showing the final opening up of the bag bottom preparatory to pasting and the one at the upper left showing a bag with its bottom in position preparatory to the final folding of the flaps;

Fig. '7 is a transverse section taken along line l'-'l of Fig. 6;

Fig. 8 is a top plan view of the mechanism shown Fig. '7 and additionally shows the second and oppositely disposed rotor and flap-folding finger together with a bag bottom being folded as it is carried by the cylinder;

Fig. 9 is a schematic view of the left-hand rotor of Fig. 8- and shows the movement of the flapfolding finger during one complete revolution of the rotor;

Fig. 10 is an enlarged fragmentary schematic side elevational view of part of the cylinder shown in Fig. 6 and illustrates the path of travel of the ends of the fiap fingers as theyare moved into and out of overlying relationship with respect to the cylinder;

Fig. 11 is an enlarged detail section of the finger end of the mechanism shown in Fig. 7 and shows in more detail the exact mounting of the finger on the rotor;

Fig. 12 is a bottom plan view of the mechanism shown in Fig. ll;

Fig. 13 is a development of the outer cam for controlling oscillation of the flap'folding finger;

Fig. 14 is a development of the inner cam for controlling oscillation of the flap-folding finger; and

Figs. 15, 16 and 17 are detail perspective views showing the final folding operation in the formation of a bag bottom.

Referring to the drawings in detail, the inven tion as illustrated is embodied in a machine for making automatic paper bags and includes a base A, a bottorner section B including a cylinder C and flap-folding mechanisms D constructed in accordance with this invention and adapted to be driven through suitable connections from a fluid or other type of motor E.

The bottomer section B includes a front frame member and a rear frame member 5 which are adapted to rotatably support the moving mechanisms of the machine.

The driving motor E is suitably secured to the rear frame member 6 and drives a back shaft 1 through suitable gear connections 8. A transverse shaft 9 is journalled between the front and rear frame members and is operatively driven from the back shaft l through a pair of beveled gears l9, ill. The rear end of the shaft 9 carries a pinion gear H rigidly affixed thereto which is i adapted to transmit power to the cylinder C through the medium of intermediate gears l2 and i3 and a cylinder gear i i.

A pair of flap folders ID constructed in accordance with this invention are mounted upon the front and rear frame members in a position overlying the upper surface of the cylinder C and are so disposed that the flap-folding fingers thereof move through an orbital path lying in a general plane approximately 45 from the horiwhich rotatably supports a shaft 2! in suitable bearings 22, 22. The lower end of the shaft 2! is provided with a bevel gear 23 which meshes with a similar bevel gear afiixed to the intermediate portion of the shaft ii. The upper end of the shaft 24 is provided with a flange 25 to which is M rigidly afiixed a generally elliptical rotor generally indicated at 26 as by a plurality of bolts 27. A sun gear 28 is rigidly afiixed to the upper end of the bearing boss 2t and carries within it the upper bearing 22 which rotatably supports the shaft 2].

One end of the rotor it is provided with a depending bearing boss 29 which rotatably supports a shaft 30 through a pair of spaced bearings 3i, 3!. It will be noted that the axis of the shaft 30 is disposed in spaced parallel alignment with the axis of the shaft 24. The lower end of the shaft 30 is bifurcated to provide a pair of legs 32. 32 between which is pivotally mounted a flapfolding finger generally indicated at 3-3 as by a pivot shaft 34.

The flap-folding finger 33 includes a finger portion 35 extending in one direction and a counter-balanced portion 35 extending in the opposite direction. The finger portion 35 carries on its upper surface a spheroidal cam follower 31 engageable with the face of an inner cylinder cam 38 secured to the depending bearing boss 29. Similarly, the counter-balanced portion 36 is provided with a cam follower 38 engageable with the face of an outer cylinder cam 'lil mounted upon the inner cam 38. The orientation of the cams 38 and 48 with respect to the bearing boss 29 may be readily determined by comparing the line X on Fig. 12 of the drawings with the corresponding lines marked X on the cam development Figs. 13 and 14.

The shaft 3% is provided intermediate its ends with a gear l! rigidly afiixed thereto and is operably connected to the sun gear 28 through the medium of an intermediate or idler gear 422 rotatably mounted upon a depending stub shaft 43 afiixed to the rotor 21?. In this manner as rotary movement is imparted to the rotor 25 by rotation of the shaft 21 the shaft 3%] and its associated fiap folding finger 33 will be maintained in fixed angu lar position during such rotation (see Fig. 9) as the result of the gear connections between it and the sun gear 28 which, of course, remains stationary.

Rotation of the rotor 26 in this manner, of course, will effect relative rotary movement between the shaft 3E! and its associated bearing boss 29, and the engagement between the cam followers and wit. the respective cylinder came 38 and 49 will thus cause the folding finger 33 to move through one cycle of oscillation about its pivot shaft 3 5 during each revolution of the rotor and in a direction normal to the general plane of rotation thereof.

The effect of oscillating the folding finger 33 in the manner described above may be clearly understood by reference to 3 and 10 of the drawings. Fig. 8 shows the arcuate path of movement of the finger ends 35 through their general plane of rotation during the time that they are moved into and out of overlying relationship with respect to the cylinder (3, and Fig. 10 shows the path of movement of the ends of the finger portions 35 as the result of oscillation thereof while overlying the cylinder as effected by the action of the cylinder cams 38 and 36. In Fig. 10 the line AA is parallel to a tangent of the cylinder and is located substantially in the general plane of orbital movement of the fingers without oscillation. The line B--B in the same figure clearly shows the arcuate path of movement taken by the ends of the fingers as a result of oscillating the same, and it will be seen that their path of movement, during at least a substantial portion of the time they overlie a portion of the cylinder, conforms generally to the curvature of the cylinder surface, and thus the fingers are enabled to more readily and more controllably eifect folding of the inner bottom flap onto the bottom of a bag carried by the cylinder. Since the axis of the pivot shaft 34 of the flapfolding fingers 33 is parallel to the general plane of movement thereof the oscillatory movement of the fingers 33 will, of course, be in a plane generally normal thereto.

Each rotor 26 may be provided with a counterbalance 4 located in the end opposite that carrying the finger 33 in order to eliminate vibration when the machine is in operation.

Each rotor 25 may also be provided with suitable oil seals enclosing the gear train comprised of the sun gear 28, the finger-shaft gear ll and the intermediate gear d2 so that the interior of the rotor may be filled with grease or other lubricant.

By reference to Fig. 6 of the drawings it will be seen in the upper right-hand quadrant of the cylinder C that the bottom of a bag carried by the cylinder is being completely opened by the co-action between the cylinder and a pair of forming shoes 45, 45 mounted on the machine frame. From this station continued rotation of the cylinder in a counterclockwise direction as viewed in Fig. 6 causes the bottom to be tucked into engagement with the appropriate front clamps 45 and rear clamps 41, then under the paste segment 48 and finally into the final fiapfolding station shown in the upper left quadrant of the figure. At this point the flap-folding mechanisms D become effective to fold the rear or inner bottom fiap 49 onto the bag bottom while the front or outer bottom fiap 56 becomes engaged by a fixed folding shoe 5! mounted on the main frame. It will be appreciated that the speed of rotation of the flap-folder rotor 26 together with its effective radius, including the length of the finger portions 35 are such that the speed of advance of the finger portions 35 during at least the major portion of the time they are overlying the surface of the cylinder C is sufficiently greater than the peripheral speed of the cylinder that the fiap 49 will be folded over onto the bottom portion of the bag while both the cylinder and flapfolding mechanisms continue to move. After the inner fiap 49 has thus been folded down into position overlying the bag bottom continued movement of the cylinder, of course, effects folding of the front or outer flap 50 thereover as the result of the sliding engagement between it and the folding shoe 5 I.

It is, of course, to be understood that various details of arrangements and proportions of parts may be modified within the scope of the appended claims.

I claim:

1. In a machine for making bags wherein is provided a bottomer section having a final fiapfolding station and including a bag-advancing cylinder and means for folding the outer fiap of a bag bottom onto the inner flap thereof; the 00111- bination of means for folding the inner bottom flap onto the bottom of a bag including a rotor, a flap-folding finger bodily movable by said rotor in an orbital path lying in a plane generally parallel to a tangent of said cylinder with a por tion of said path overlying said cylinder, means carried by said rotor for maintaining said finger in substantially fixed angular position with respect to a plane passing through the axis of rotation of said rotor, and means for oscillating said finger during each revolution of said rotor where by to substantially conform the path of movement of said finger to the configuration of said cylinder during at least the major portion of the time that said finger overlies said cylinderv 2. In a machine for making bags wherein is provided a bottomer section having a final flapfolding station and including a bag-advancing cylinder and means for folding the outer fiap of a bag bottom onto the inner flap thereof; the combination of means for folding the inner bottom flap onto the bottom of a bag including a rotor, a flap-folding finger bodily movable by said rotor in an orbital path lying in a plane generally parallel to a tangent of said cylinder with a portion of said path overlying said cylinder, means carried by said rotor for maintaining said finger in substantially fixed angular position with respect to a plane passing through the axis of rotation of said rotor, and means for oscillating said finger during each revolution of said rotor whereby to substantially conform the path of movement of said finger to the configuration of said cylinder during at least the major portion of the time that said finger overlies said cylinder, the speed of advance of said finger being greater than the peripheral speed of said cylinder.

3. In a machine for making bags wherein is provided a bottomer section having a final flapfolding station and including a bag-advancing cylinder and means for folding the outer flap of a bag bottom onto the inner fiap thereof; the combination of means for folding the inner bottom flap onto the bottom of a bag including a rotor, a flap-folding finger bodily movable by said rotor in an orbital path lying in a plane generally parallel to a tangent of said cylinder with a portion of said path overlying said cylinder, means carried by said rotor for maintaining said finger in substantially fixed angular position with respect to a plane passing through the axis of rotation of said rotor, and cam-controlled means for oscillating said finger during each revolution of said rotor whereby to substantially conform the path of movement of said finger to the configuration of said cylinder during at least the major portion of the time that said finger overlies said cylinder.

4. In a machine for making bags wherein is provided a bottomer section having a final fiapfolding station and including a bag-advancing cylinder and means for folding the outer flap of a bag bottom onto the inner fiap thereof; the combination of means positioned at said final flapfolding station for folding a bottom flap onto the bottom of a bag being formed'and comprising a constantly rotating flap-folder unit including a rotor operably connected to said machine, a flapfolding finger rotatably mounted on said rotor and projectable across said cylinder at said flapfolding station, and gear means operably associated with said rotor for maintaining said finger in substantially fixed angular position with respect to a plane passing through the axis of rotation of said rotor while said finger is bodily moved through an orbital path by said rotor, the speed of advance of said finger through said orbital path being greater than the peripheral speed of said cylinder.

5. In a machine for making bags wherein is provided a bottomer section having a final flapfolding station and including a bag-advancing cylinder and means for folding the outer fiap of a bag bottom onto the inner fiap thereof; the combination of means positioned at said final flap-folding station for folding a bottom fiap onto the bottom of a bag being formed and comprising a constantly rotating flap-folder unit including a rotor operably connected to said machine, a flap-folding finger rotatably mounted on said rotor and projectable across said cylinder at said flap-folding station, gear means operably associated with said rotor for maintaining said finger in substantially fixed angular position with respect to a plane passing through the axis of rotation of said rotor while said finger is bodily moved through an orbital path by said rotor, the speed of advance of said finger through said orbital path being greater than the peripheral speed of said cylinder, and means for oscillating said finger during each revolution of said rotor whereby to substantially conform the path of movement of said finger to the configuration of said cylinder during at least the major portion of the time that said finger overlies said cylinder.

6. In a machine for making bags wherein is provided a bottomer section having a final flapiolding station and including a bag-advancing cylinder and means for folding the outer flap of a bag bottom onto the inner flap the cot the combination of means positioned at said final flap-folding station for folding a bottom flap onto the bottom of a bag being formed and comprising a constantly rotating flap-folder unit including a rotor operably connected to said machine, a fiap folding finger rotatably mounted on said rotor and proiectable across said cylinder at said flapfolding station, gear means operably associated with said rotor for maintaining said finger in substantially fixed angular position with respect to a plane passing through the axis of rotation of said rotor while said finger is bodily moved through an orbital path by said rotor, the speed of advance of said finger through said orbital path being greater than the peripheral speed of said cylinder, and cam-controlled means for oscillating said finger during each revolution of said rotor whereby to substantially conform the path of movement of said finger to the configuration of said cylinder during at least the major portion of the time that said finger overlies said cylinder.

7. Flap-folding means for a bagmaking ma chine comprising a rotor, a flap-folding finger rotatably mounted on said rotor, means operably associated with said rotor for maintaining said finger in substantially fixed angular relation with respect to one reference plane while being moved by said rotor through an orbital path generally lying anoter reference plane, and means for oscillating said finger in a direction substantially normal to the general plane of said orbital movement during each revolution of said rotor.

8. Flap-folding means for a bagmaking ma chine comprising a rotor, at flap-folding finger rotatably mounted on said rotor, gear means operably associated with said rotor for maintai ing said finger in substantially fixed angular relation w espect to one reference plane while is moved 3; said rotor through an orbital path generally lying in another reference plane, and cam-controlled means for oscillating said finger in a direction substantially normal to the general lane of said orbital movement during each revolution of said rotor.

9. Flap-folding means for a bagmaking machine including a bottomer section having a main frame and a bag-advancing cylinder rotatably mounted on said frame; comprising a pair of gears aiiixed to the frame of said machine with their axes disposed in spaced parallel relationship on opposite sides of said cylinder and parallel to a plane passing through the center thereof, a pair of shafts rotatably mounted on said frame and each having one end extending through one of said gears and projecting therebeyond, a rotor ai-Tixed to the projecting end of each of said shafts, a shaft rotatably mounted on each said rotor with its axis in substantially parallel alignment with said first-mentioned shafts, a flap-folding finger mounted on one end of each of the said last-mentioned shafts and projectable across said cylinder, a gear mounted on the other end of each of said last-mentioned shafts, means for operably connecting said lastmentioned and said fixed gears on each of said rotors whereby to maintain said fingers in substantially fixed angular relation with respect to one reference plane while being moved by said rotors through orbital paths generally lying in a reference plane substantially normal to said firstmentioned reference plane, and means for driving said rotors in opposite dir ctions.

10. Flap-folding means for a bagmaking machine including a bottomer section having a main frame and a bag-advancing cylinder rotatably mounted on said frame; comprising a pair of gears affixed to the frame of said machine with their axes disposed in spaced parallel relationship on opposite sides of said cylinder and parallel to a plane passing through the center thereof, a pair of shafts rotatably mounted on said frame each having one end extending through one of said gears and projecting therebeyond, a rotor affixed to the projecting end of each of said shafts, a shaft rotatably mounted on each said rotor with its axis in substantially parallel alignment with first-mentioned shafts, a flap-folding finger pivotally mounted on one end of each of the said last-mentioned shafts and projectable across said cylinder, a gear mounted on the other end of each of said last-mentioned shafts, means for operably connecting said last-mentioned and said fixed gears on each of said rotors whereby to maintain said fingers in substantially angular relation with respect to one reference plane while being moved by said rotors through orbital paths generally lying in a reference plane substantially normal to said first-mentioned reference plane, means for driving said rotors in opposite directions, and means for oscillating said fingers in a direction substantially normal to the general plane or said orbital paths during each revolution of said rotors.

ll. Flap-folding means for a bagmaking machine including a bottomer section having a main frame and a bag-advancing cylinder rotatably mounted on said frame; comprising a pair of gears affixed to the frame of said machine with axes disposed in spaced parallel relationship on opposite sides of said cylinder and parallel to a plane passing through the center thereof, a pair of shafts rotatably mounted on said frame and each having one end extending through one of said gears and projecting therebeyond, a rotor aifixed to the projecting end of each of said shafts, shaft rotatably mounted on each said rotor with its axis in substantially parallel alignment with said first-mentioned shafts, a flap-folding finger pivotally mounted on one end of each of the said last-mentioned shafts and projectable across said cylinder, a gear mounted on the other end of each of said last-mentioned shafts, means for operably connecting said last-mentioned and said fixed gears on each of said rotors whereby to maintain said fingers in substantially fixed angular relation with respect to one reference plane while being moved by said rotors through orbital paths generally lying in a reference plane substantially normal to said first-mentioned reference plane, means for driving said rotors in opposite directions, and cam-controlled means for oscillating said fingers in a direction substantially normal to the general plane of said orbital paths during each revolution of said rotors.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 635,090 Claussen et a1. Oct. 17, 1899 782,948 Claussen et al Feb. 21, 1905 1,030,783 King et al. June 25, 1912 

